Clear Water, Pure Coffee

Wageningen Climate Solutions

Photography: Shutterstock

BY Kenneth van Zijl - September 2019

Coffee bean cultivation in Colombia is suffering due to climate change. A lauded collaboration between Wageningen and the private sector that focused on smart water management is making coffee cultivation cleaner and more resilient.

Your cup of coffee is highly likely to have been brewed with beans from Colombia. The South American country is one of the world’s leading coffee producers. The arabica coffee beans grown there are celebrated for their sublime aroma.

But Colombian coffee cultivation is vulnerable to climate change. Conditions alternate between periods of extreme drought and heavy rainfall. These fluctuations in the availability of water are a disaster for coffee plantations because a few weeks without water can be enough to make a farmer’s harvest fail.

Fluctuations in the availability of water are a disaster for coffee plantations

The arabica coffee beans grown in Colombia are celebrated for their sublime aroma. Photo: Neil Palmer, CIAT


The Eje Cafetero – the coffee axis – runs from north to south in the west of the country. The geographical location in combination with the steep slopes means the farmers do not have irrigation systems: they are dependent on rain for their water supplies. There are more than half a million small coffee farmers, who can lose up to 40 per cent of their harvest in a season due to a shortage or excess of water. This has huge consequences for their income and the social structures around the plantations.

Responsible use of the available water resources is therefore crucially important. In 2013, Manos al Agua, a public-private partnership, was started with the aim of working towards sustainable water use in the coffee industry. The programme, which ran for five years, involved the Colombian Coffee growers Federation (FNC), the Dutch Ministry of Foreign Affairs, the Colombian government, Nestlé and Nespresso, Wageningen University & Research and the Colombian research institute Cenicafé (see inset).

Laura Miguel Ayala and Angel de Miguel Garcia are Spanish hydrologists who work as researchers at Wageningen University & Research. They were closely involved in Manos al Agua (literally ‘hands on water’) from the start.

The partners of Manos al Agua involved worked closely together in the implementation of the project.


Afterwards, the contaminated washing water is dumped in the rivers and streams

The project encompassed 25 locations that together stretched across several hundred kilometres from north to south. Each location was in the drainage basin of a river or stream where small communities of farmers and their families lived and had their plantations. Because the plantations were scattered, the researchers were able to obtain a good impression of the water system in the whole area. A total of 11,000 farmers were involved in Manos al Agua.

The Wageningen scientists regularly worked on site at the Colombian coffee plantations in the course of the project. Laura Miguel Ayala: “Coffee farmers in Colombia mainly grow arabica on small plots of one to one and a half hectares. Most plots are on the slopes of the Andes at altitudes of 1000 to 2500 metres. As you can imagine, many plantations are quite remote. The cherries that contain the beans are picked by hand. I visited the plantations regularly and I developed huge respect for the coffee farmers because it is incredibly hard work.”

The entire process of picking and hulling the coffee cherries takes place on the small plantations. Photo: Angel de Miguel Garcia


It is not just the fluctuating supply of water that is a problem for families growing coffee in the Eje Cafetero. The available water is also used in the production process and the environmentally polluting substances that are released in that process are discharged into the streams and rivers, where they become a threat to the people living in the villages bordering the plantations.

“The entire process of picking and hulling the coffee cherries takes place on the small plantations. The cherries have to be hulled within 24 hours or otherwise they will start to rot and the coffee beans will be worthless,” says researcher Angel de Miguel Garcia.

“Each farmer has a small machine that removes the pulp from the bean. Then the beans undergo a fermentation process to remove every trace of pulp. A lot of washing water is used in that process. Afterwards the water, which is contaminated with organic compounds and fats, is dumped in the rivers and streams. That reduces the oxygen levels, even killing off fish as a result.”

Man harvesting coffee beans. The cherries that contain the beans are picked by hand. Photo: Alf Ribeiro / Shutterstock


In the project, the Wageningen researchers focused on developing a water purification method. The key criteria were that the method should be cheap and robust and require minimum maintenance. “You can’t ask a farmer with a small plot to spend a thousand euros on a water purification plant. And we mustn’t forget they are coffee farmers, not water purification engineers,” explains Angel de Miguel Garcia.

The solution was literally there for the taking. Angel de Miguel Garcia: “When we were investigating the water quality, it turned out that not all farmers discharged the washing water into the rivers. There were also farmers who let that water run off into the soil. After analyses at various locations, we found that the water that reached the water courses via the soil was much less polluted.”

Underground processing by microorganisms and roots in the soil has a purifying effect. The researchers from Wageningen and Colombia and Nestlé’s water specialist used this finding as the basis for their concept. This means that the organic pollution of the water is being dealt with using natural methods. Such filters consisting of soil, parts of plants and root systems are called ‘green filters’.

A coffee-farming family. Photo: Manos al Agua

The pluviometer can be used to measure the rainfall in the coffee plantation. Photo: Angel de Miguel Garcia

The wet process serves to remove the parchment from the beans in order to obtain dry coffee ready for roasting. Photo: Angel de Miguel Garcia


The green filters developed by the Wageningen researchers helped achieve improvements in the water quality at 80 per cent of the locations. Angel de Miguel Garcia: “We have calculated that these measures have prevented the pollution of 10 billion litres of water per year. That amounts to a positive impact on the climate and on the living conditions of the coffee farmers.”

The green filter test. Photo: Angel de Miguel Garcia

The project came to an end in 2018. One year before the close of the project, Manos al Agua won the Planeta Azul Award, a prize that the Colombian government has given since 1993 to projects that make an innovative contribution to the preservation and restoration of vulnerable water systems in Colombia.


The researchers felt the collaboration with Nestlé and Nespresso went well, says Angel de Miguel Garcia. “It took a bit of getting used to. As a scientist, I’m used to doing independent academic research and suddenly I was sitting down with local authorities, Colombian researchers and people from the private sector.”

However, the scientists really benefited from the mindset of the big companies. Angel de Miguel Garcia: “Multinationals tend to be quicker in settling matters and taking decisions. The people at Nestlé in particular were incredibly inspiring and motivating. I liked that.”

The green filters helped achieve improvements in the water quality at 80 per cent of the locations


The Manos Al Agua programme is a collaborative venture between the Dutch and Colombian governments, the multinationals Nestlé and Nespresso, Wageningen University & Research and the Colombian research centre Cenicafé. It is geared to improving the socio-economic position and sustainability of Colombian coffee farmers at a time of climate change and associated fluctuations in water resources.

Sustainable coffee production requires increasing awareness among coffee farmers of the need for effective water management. That goes further than simply developing new techniques for capturing and distributing water. Take the introduction of new crops, improved farming technology, reforestation and the smarter use of water, for example.

Workshops were also developed for the communities near the plantations with the aim of getting them to use water more responsibly and reducing the pollution in the local environment.

The idea is that in the long run, the programme will improve the competitive position of the Colombian coffee families, who will be better able to cope with water shortages and surpluses while also causing less pollution to water supplies.

For more information about WUR’s research on sustainable coffee, please visit our website.

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